cbuildbot: drop options.ts_mon_task_num reference

We deleted the command line flag that created this, so drop the ref too.
The default when the flag wasn't specified was 0, and if we don't pass
the arg to this func call, it'll still be 0.

BUG=chromium:1011475
TEST=CQ passes

Change-Id: I16b54f4c24d2e3c4bf6d5eed2db738d08b56aeff
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1962711
Reviewed-by: David Burger <dburger@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cbuildbot.py b/scripts/cbuildbot.py
index 4a3fa33..b89f75a 100644
--- a/scripts/cbuildbot.py
+++ b/scripts/cbuildbot.py
@@ -735,8 +735,7 @@
 
   if run_type == _ENVIRONMENT_PROD:
     cidb.CIDBConnectionFactory.SetupProdCidb()
-    context = ts_mon_config.SetupTsMonGlobalState(
-        'cbuildbot', indirect=True, task_num=options.ts_mon_task_num)
+    context = ts_mon_config.SetupTsMonGlobalState('cbuildbot', indirect=True)
   elif run_type == _ENVIRONMENT_DEBUG:
     cidb.CIDBConnectionFactory.SetupDebugCidb()
     context = ts_mon_config.TrivialContextManager()